The helmsman and the physician. An analogy for one who bears a caretaking role — a ruler, a teacher, a sage. Sailors may revile the helmsman (κυβερνήτης), the sick the physician (ἰατρός), but no other will thereby appear worth heeding: only the one who knows his craft brings the ship to safety (τὸ σωτήριον) and the body to health (τὸ ὑγιεινόν). The governing discipline is action.
Duty in spite of reproaches. Hence the moral: one who knows the good of those in his charge is bound to work it despite their abuse — not for their approval but for their benefit. The murmuring of the governed does not annul the obligation of the governor; on the contrary, to give way before abuse would be to betray the craft itself. A direct continuation of 06-50 (act even against their will, when justice bids) and of the portrait in 06-30 (Antoninus bore unjust reproaches while doing his work).
Parallels. 06-50 (action against others' will); 06-30 (to bear reproaches without retaliating); Med. 5.28; 9.27; the classic image of the "helmsman" / "physician" of the soul — Plato, Rep. VI 488a–489a (the ship of state), Epictetus Disc. 3.23 (the philosopher as physician).